At the new hunt screen (where you start a hunt from) go to level and put it in hunter mode. Now go down to the weapon select and choose any gun you want. Go back up to the level option and put it back on beginner. When you go down to the gun select it will still be on that gun. (If you switch in between the guns after doing the following steps when you come back around that gun won't be there any more.)Go to start and you can begin the hunt with that gun.